Liquid crystal display device and method of manufacturing the same

ABSTRACT

In a liquid crystal display device comprising a first substrate  101  having a color filter, a second substrate  131  and a liquid crystal layer disposed therebetween, a color filter layer  110  is disposed on a protection film  108  of a thin film transistor formed on the first substrate  101  so as to be partitioned by a light shielding portion  111,  and a common electrode  103  is disposed thereon. A pixel electrode to be connected to a source electrode  107  is disposed through a through hole formed in an overcoat layer (interlayer separation film)  112.  On the first substrate below the color filter layer  110  are provided plural scan signal electrodes, plural video signal electrodes crossing the scan signal electrodes in a matrix form, plural thin film transistors formed in association with the crossing points between the electrodes. Each pixel is provided with a common electrode  103  which is connected over plural pixels through a common electrode wire to supply reference potential, and a pixel electrode  114  which is connected to the corresponding thin film transistor and disposed so as to confront the common electrode in the pixel area.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an active matrix type liquidcrystal display device which thin film transistors (TFT) are arranged ina matrix form and these thin film transistors are used as switchingelements.

[0003] 2. Description of the Related Art

[0004] An active matrix type TFT (Thin Film Transistor: hereinafterabbreviated as “TFT”) liquid crystal display device in which TFTs areformed in a matrix arrangement on a glass substrate and these TFTs areused as switching elements has been developed as a high-qualityflat-face display. In a twisted nematic (hereinafter abbreviated as“TN”) type active matrix crystal display device which has been hithertowidely used, transparent electrodes which are formed on two glasssubstrates so as to confront each other are used as electrodes fordriving a liquid crystal layer. By applying a voltage to liquid crystalmolecules which are arranged in parallel to the substrate surface undernon-voltage application state (i.e., “white” display state), thedirection of the orientation vector of the liquid crystal moleculesvaries from the “white” display state to the direction of the electricfield in accordance with the applied voltage, whereby the “white”display state is gradually varied to a “black” display state.

[0005] However, the inherent behavior of the liquid crystal voltagesunder voltage-applied state causes a problem that the angle ofvisibility of the TN type liquid crystal display device is small. Theproblem that the angle of visibility is small is particularly remarkablein the rise-up direction of the liquid crystal molecules under a halftone display state.

[0006] A technique as disclosed Japanese Laid-open Patent ApplicationNo. Hei-4-261522 or Japanese Laid-open Patent Application No.Hei-6-43461 has been proposed as a method of improving theangle-of-visibility characteristic of the liquid crystal display device.According to these techniques, a liquid crystal cell in which liquidcrystal molecules are homeotropically oriented is created, and it issandwiched between two polarizing plates arranged so that thepolarization axes thereof are perpendicular to each other. As shown inthe drawings of the above publications, a slant electric field isgenerated in each pixel by using a common electrode having an openingportion to make two or more crystal liquid domains in each pixel,thereby enhancing the angle-of-visibility characteristic. In theJapanese Laid-open Patent Application No. Hei-4-261522, the slantdirection of the liquid crystal molecules when the voltage is applied isparticularly controlled to achieve high contrast.

[0007] Further, as disclosed in Japanese Laid-open Patent ApplicationNo. Hei-6-43461, an optical compensator is used to enhance theangle-of-visibility characteristic for black, as occasion demands.Further, in Japanese Laid-open Patent Application No. Hei-6-43461, fornot only a homeotropically-oriented type of liquid crystal cell, butalso a TN-oriented type liquid crystal cell, each pixel is divide intotwo or more domains by using slant electric field, thereby enhancing theangle-of-visibility characteristic.

[0008] Japanese Patent No. Hei-5-505247 proposes an IPS(In-Plane-Switching) type liquid crystal display device in which twoelectrodes are formed on one substrate and a voltage is applied acrossthese two electrodes to generate electric field in parallel to thesubstrate in order to rotate the liquid crystal molecules while keepingthe molecules in parallel to the substrate. According to this system,the major axis of each liquid crystal molecule is prevented from risingup with respect to the substrate when the voltage is applied. Therefore,the variation of the birefringence of the liquid crystal molecules whenthe direction of the visual angle is varied is small, and thus the angleof visibility is large

[0009] An IPS type active matrix liquid crystal device in which both oftwo electrodes are provided on one of substrates as described above willbe described hereunder. The IPS type TFT liquid crystal display deviceis constructed as shown in FIGS. 12A and 12B. FIG. 12A is across-sectional view taken along A-A′ line of a plan view of FIG. 12B.

[0010] First, a gate electrode 1202 and a common electrode 1203 areformed of Cr on a glass substrate 1201, and then a gate insulating film1204 of silicon nitride is formed so as to cover these electrodes 1202and 1203. Then, a semiconductor film 1205 of amorphous silicon is formedthrough a gate insulating film 1204 on the gate electrode 1202, and itfunctions as an active layer of transistors. A drain electrode 1206 anda source electrode 1207 are formed of molybdenum so as to be superposedover a part of the pattern of the semiconductor film 1205, and aprotection film 1208 of silicon nitride is formed so as to cover all theabove elements.

[0011] As shown in FIG. 12B, a one-pixel area is disposed between thesource electrode 1207 and the drawn-out common electrode 1203.Thereafter, an orientation film ORI 1 is formed on the surface of anactive matrix substrate in which a plurality of unit pixels thusconstructed are arranged in a matrix form. The surface of theorientation film IRI1 is subjected to a rubbing treatment.

[0012] Further, a color filter layer 1232 is formed on a countersubstrate 1231 of glass so as to be partitioned by light shieldingportions 1233, and a protection film 1234 is formed on these elements.An orientation film ORI2 is also formed on the surface of the protectionfilm 1234, and the surface of the orientation film ORI2 is alsosubjected to the rubbing treatment.

[0013] The glass substrate 1201 and the counter substrate 1231 aredisposed so that the orientation film ORI1 and the orientation film ORI2are confronted to each other, and liquid crystal composition 1240 isdisposed between the orientation films ORI1 and 0RI2. Further, apolarizing plate 1251 is formed on each of the outer surfaces of theglass substrate 1201 and the counter substrate 1231. Each of the lightshield portions 1233 through which the color filter layer 1232 ispartitioned is partially disposed on a thin film transistor formed ofthe semiconductor layer 1205.

[0014] In the active matrix type liquid crystal display device thusconstructed, when no electric field is applied to the liquid crystalcomposition 1240, liquid crystal molecules 1241 a are kept to besubstantially parallel to the extending direction of the electrodes, andhomogeneously oriented. That is, the liquid crystal molecules 1241 a areorientated so that the intersecting angle between the direction of themajor axis (optical axis) of the liquid crystal molecules 1241 a and thedirection of the electric field formed between the source electrode 1207and the drawn-out common electrode 1203 is set to a value in the rangewhich is above 45° and less than 90°. The glass substrate 1201 and thecounter substrate 1231 arranged so as to confront each other aredisposed in parallel to the orientation direction of the liquid crystalmolecules 1241 a. The permittivity anisotropy of the liquid crystalmolecules 1241 a is set to a positive value.

[0015] Here, when a voltage is applied to the gate electrode 1202 toswitch on the thin film transistor (TFT), a voltage is applied to thesource electrode 1207 to induce electric field between the sourceelectrode 1207 and the common electrode 503 disposed so as to confrontthe source electrode 1207. The liquid crystal molecules 1241 a areorientationally turned to liquid crystal molecules 1241 b. The liquidcrystal molecules 1241 b are kept to be substantially parallel to thedirection of the electric field generated between the source electrode1207 and the common electrode 1203 disposed so as to confront the sourceelectrode 1207.

[0016] By setting the polarization transmission axis of the polarizingplate 1251 at a predetermined angle, the transmittance of light can bevaried by the movement of the liquid crystal molecules as describedabove.

[0017] As described above, with the IPS type active matrix liquidcrystal display device, the contrast can be given without anytransparent electrode.

[0018] In the IPS type TFT liquid crystal display device, the major axisof the liquid crystal molecules is substantially parallel to the flatsurface of the substrate, and it does not rise up even when a voltage isapplied. Therefore, variation in brightness when a viewing direction isvaried is little, and thus the visual characteristic is greatlyenhanced.

[0019] Further, a paper (Journal of Applied Physics, Vol. 45, No.12(1974) 5466) or Japanese Laid-open Patent Application No.Hei-10-186351 discloses such a system that liquid crystal moleculeshaving positive permittivity anisotropy are homeotropically orientedperpendicularly to the substrate and these molecules are felled and putin parallel to the substrate by the electric field directing in parallelto the substrate, in addition to an IPS mode. At this time, the liquidcrystal molecules which are homeotropically oriented due to thedirection of the electric field are divided into two or more areas whichare different in the slant direction of the liquid crystal molecules.

[0020] However, in the IPS system, the color filter layer is disposedbetween the liquid crystal layer and the counter substrate, and thus theelectric field which will be formed when potential is applied betweenthe source electrode and the drawn-out common electrode adverselyaffects the color filter layer and degrades the display characteristicof the active matrix type liquid crystal display device. That is, thepigments constituting the color filter layer contain sodium ions, etc.,and thus when electric field is applied to the color filter layer,charges are trapped there and the color filter layer is charged up. Whenthe color filter layer charges up, undesired electric field is appliedto the liquid crystal molecules below the charge-up area of the colorfilter layer at all times, so that the display characteristic isadversely effected.

SUMMARY OF THE INVENTION

[0021] The present invention has been implemented to overcome the aboveproblems, and has an object to provide a liquid crystal display devicewhich can suppress occurrence of color shade.

[0022] Another object of the present invention is to provide amanufacturing method which can easily manufacture the liquid crystaldisplay device.

[0023] In order to attain the above objects, according to a first aspectof the present intention, there is provided a liquid crystal displaydevice including a transparent first substrate and a transparent secondsubstrate, and a liquid crystal layer and a color filter layersandwiched between the transparent first and second substrates,characterized in that the color filter layer is disposed on the firstsubstrate; the liquid crystal layer is disposed between the color filterlayer and the second substrate; a plurality of scan signal electrodes, aplurality of video signal electrodes crossing to the scan signalelectrodes in a matrix form and a plurality of thin film transistorsformed in association with the respective crossing points of the scansignal electrodes and the video signal electrodes are provided on thefirst substrate below the color filter layer; at least one pixel isconstructed in each of areas surrounded by the plural scan signalelectrodes and the plural video signal electrodes; each pixel has acommon electrode which is commonly connected to plural pixels throughcommon electrode wiring to supply reference potential to the pixels anda pixel electrode which is connected to the corresponding thin filmtransistor and disposed so as to confront the common electrode in apixel area; the common electrode and the pixel electrode are disposed indifferent layers through an interlayer separation film of transparentinsulating material; electric field having a component which isdominantly parallel to the first substrate is produced in the liquidcrystal layer by applying a voltage across the common electrode and thepixel electrode; and the liquid crystal molecules before the voltage areoriented substantially in parallel to the first substrate.

[0024] According to a second aspect of the present invention, there isprovided a liquid crystal display device including a transparent firstsubstrate and a transparent second substrate, and a liquid crystal layerand a color filter layer sandwiched between the transparent first andsecond substrates, characterized in that the color filter layer isdisposed on the first substrate; the liquid crystal layer is disposedbetween the color filter layer and the second substrate; a plurality ofscan signal electrodes, a plurality of video signal electrodes crossingto the scan signal electrodes in a matrix form and a plurality of thinfilm transistors formed in association with the respective crossingpoints of the scan signal electrodes and the video signal electrodes areprovided on the first substrate below the color filter layer; at leastone pixel is constructed in each of areas surrounded by the plural scansignal electrodes and the plural video signal electrodes; each pixel hasa common electrode which is commonly connected to plural pixels throughcommon electrode wiring to supply reference potential to the pixels anda pixel electrode which is connected to the corresponding thin filmtransistor and disposed so as to confront the common electrode in apixel area; the common electrode and the pixel electrode are disposed indifferent layers through an interlayer separation film of transparentinsulating material; electric field having a component which isdominantly parallel to the first substrate is produced in the liquidcrystal layer by applying a voltage across the common electrode and thepixel electrode; and the liquid crystal molecules before the voltage areoriented substantially vertically to the first substrate.

[0025] Accordingly, under the electric field produced by applying thevoltage across the common electrode and the pixel electrode, the liquidcrystal in the liquid crystal layer is automatically divided into two ormore areas, and felled so as to be parallel to the substrate, so thatthe electric field occurring in the liquid crystal layer has no effecton the color filter layer.

[0026] In the liquid crystal display device of the present invention, atleast one of the common electrode and the pixel electrode may be formedof a transparent conductive film in order to suppress reduction of theopening degree. Further. the liquid crystal display device may bedesigned so that the pixel electrode is formed of a transparentconductive film, the common electrode is formed of metal such as Cr orthe like and the light shielding layer for shielding TFT from light isformed of the same layer as the common electrode.

[0027] Further, the liquid crystal display device of the presentinvention has at least one optical compensator between the polarizingplate and the liquid crystal cell to enhance the angle-of-visibilitycharacteristic. An optically negative compensator is preferably used asthe compensator from the viewpoint of offsetting the variation ofretardation when the display device is viewed from a slant directionbecause the liquid crystal molecules under non-voltage application stateare homeotropically oriented. The same effect can be obtained by formingthe compensator of one film which is created by a biaxial stretching(orientation) method or the like, or by superposing two or moreone-axially stretched (oriented) films on each other and using theresult as a substantially optically negative one-axial compensator.Further, the initial orientation is set to the vertical orientation inprincipal, however, when the orientation direction is displaced to somedirection due to characteristics of elements, a film having positiveoptical anisotropy may be attached to compensate the displacement.

[0028] Further, in the liquid crystal display device of the presentinvention, a transparent conductive film may be provided to the oppositeside to the liquid crystal layer of the second substrate to avoid anadverse effect of static electricity or the like on the display.

[0029] According to a method of manufacturing a liquid crystal displaydevice, an initial orientation is controlled by applying a voltageacross a common electrode and a pixel electrode, and then polymerizablemonomers or olygomers which are mixed in a small amount in liquidcrystal are polymerized to make the initial orientation of the liquidcrystal further sure. When the initial orientation is controlled, thetemperature may be lowered while applying a voltage across the commonelectrode and the pixel electrode the liquid crystal layer is madeisotropic by heating, or the voltage may be merely applied across thecommon electrode and the pixel electrode. Further, the reaction of themonomers may be induced before the liquid crystal layer is madeisotropic by heating or during the heating. When the initial orientationis controlled by applying the voltage across the common electrode andthe pixel electrode at room temperature, the reaction may be inducedbefore the application of the voltage or after the application of thevoltage.

[0030] Further, the method of manufacturing the liquid crystal displaydevice according to the present invention, a pretilt angle control whichis conformed with a divisional shape is beforehand performed on thesubstrate by a rubbing or optical orienting method, thereby making thecontrol of the initial orientation extremely sure, and also in order toprevent disturbance of this orientation due to application of a drivingvoltage, polymerizable monomers or olygomers which are mixed in a smallamount in liquid crystal are polymerized, thereby achieving moreexcellent effect. Still further, in the case of the optical orientation,the division can be more surely maintained under driving operation bypolymerizing the polymerizable monomers or olygomers which are mixed ina small amount in the liquid crystal.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031]FIGS. 1A and 1B are cross-sectional view and plan view showing aliquid crystal display device according to a first mode of the presentinvention;

[0032]FIGS. 2A to 2E are cross-sectional views showing a manufacturingmethod of the liquid crystal display device according to the first mode;

[0033]FIGS. 3F and 3G are cross-sectional views showing subsequent stepsof the manufacturing method of FIGS. 2A to 2E;

[0034]FIGS. 4A and 4B are cross-sectional view and plan view showing aliquid crystal display according to a second mode of the presentinvention; and

[0035]FIGS. 5A to 5C are plan view and cross-sectional view showing theconstruction of a liquid crystal display device according to a thirdmode of the present invention;

[0036]FIGS. 6a to 6E are cross-sectional view showing a method ofmanufacturing a liquid crystal display device according to the thirdmode;

[0037]FIGS. 7A to 7C are plan view and cross-sectional view showing theconstruction of a liquid crystal display device according to a fourthmode of the present invention;

[0038]FIGS. 8A to 8E are cross-sectional views showing a method ofmanufacturing a liquid crystal display device according to the fourthmode;

[0039]FIGS. 9A and 9B are plan view and cross-sectional view showing theconstruction of a liquid crystal display device according to a fifthmode of the present invention;

[0040]FIGS. 10A to 10C are step diagrams showing a method of rubbingtreatment in the fifth mode;

[0041]FIGS. 11A to 11C are step diagrams showing another method of therubbing treatment of the fifth mode; and

[0042]FIGS. 12A and 12B are diagrams showing the construction of aconventional IPS type TFT liquid crystal display device.

DETAILED DESCRIPTION OF THE PREFERRED MODES

[0043] Preferred modes according to the present invention will bedescribed hereunder with reference to the accompanying drawings.

[0044] [First Mode]

[0045] First, a liquid crystal display device according to a first modewill be described with reference to FIGS. 1A and 1B. FIG. 1A is across-sectional view of AA′ line of a plan view of FIG. 1B.

[0046] In the liquid crystal display device according to the first mode,a gate electrode (scan signal electrode) 102 formed of Cr is disposed ona glass substrate 101, and a gate insulating film 104 of silicon nitrideis formed so as to cover the gate electrode 102.

[0047] Further, a semiconductor film 105 of amorphous silicon isdisposed through the gate insulating film 104 on the gate electrode 102,and it is designed to function as an active layer of a thin filmtransistor (TFT). Further, a drain electrode 106 and a source electrode107 are formed of molybdenum so as to be overlapped with a part of thepattern of the semiconductor film 105, and a protection film 108 isformed of silicon nitride so as to cover all the above elements. As notshown, each of the drain electrode 106 and the source electrode 107 isoverlapped with a part of the pattern of the semiconductor film 105through an amorphous silicon film doped with n-type impurities. As showin FIG. 1B, the drain electrode 106 is connected to a data line (videosignal electrode) 106 a. In other words, the drain electrode 106 isformed as a part of the data line 106 a.

[0048] In the first mode, a color filter layer 110 is disposed on theprotection film 108 so as to be partitioned by a light shielding portion111. The surfaces of the color filter layer 110 and the light shieldingportion 111 are covered by an overcoat layer (interlayer separationfilm) 112. The overcoat layer 112 is formed of a transparent insulatingmaterial which is hard to charge up.

[0049] A pixel electrode 114 connected to the source electrode 107through a through hole which is formed so as to penetrate through theprotection film 108, the light shielding portion 111 and the overcoatlayer 112 is disposed on the overcoat layer 112. On the plane, a commonelectrode 103 drawn out from a common electrode wire 103 a is formed soas to confront the pixel electrode 114 in a one-pixel area. Here, thecommon electrode 103 is disposed on the light shielding portion 111 soas to be covered by the overcoat layer 112.

[0050] Accordingly, in the first mode, the common electrode 103 isdisposed on the color filter layer 110 and the pixel electrode 114 isdisposed on the overcoat layer 112 which is formed so as to cover thecommon electrode 103 and the color filter layer 110. Each pixel isformed in an area sandwiched between the pixel electrode 114 and thecommon electrode 103.

[0051] Further, an orientation film 115 is formed on the surface of theactive matrix substrate in which the unit pixels are arranged in amatrix form as described above, that is, on the overcoat layer 112having the pixel electrode 114 formed thereon. The surface of theorientation film 115 is subjected to the rubbing treatment.

[0052] An orientation film 132 is also formed on a counter substrate 131of glass, and the surface of the orientation film 132 is also subjectedto the rubbing treatment.

[0053] The glass substrate 101 and the counter substrate 131 aredisposed so that the orientation film 115 and the orientation film 132are confronted to each other, and a liquid crystal composition layer 140is disposed between the counter substrate 131 and the orientation film115. A polarizing plate 151 is formed on the outer surface of each ofthe glass substrate 101 and the counter substrate 131. The lightshielding portion 111 through which the color filter layer 110 ispartitioned is disposed so as to be partially superposed on each filmtransistor formed of the semiconductor film 105.

[0054] In the TFT liquid crystal device thus constructed, when noelectric field is applied to the liquid crystal composition layer 140,the liquid crystal molecules in the liquid crystal composition layer 140are kept substantially in parallel to the extending direction of theelectrodes, and homogeneously orientated. That is, the liquid crystalmolecules are oriented so that the intersection angle between the majoraxis (optical axis) of the liquid crystal molecules and the electricfield direction formed between the pixel electrode 114 and the commonelectrode 103 is set to be above 45° and less than 90°, for example. Theglass substrate 101 and the counter substrate 131 disposed so as toconfront each other are in parallel to the orientation direction of theliquid crystal molecules. The permittivity anisotropy of the liquidcrystal molecules is set to a positive value.

[0055] Here, when a voltage is applied to the gate electrode 102 toswitch on the thin film transistor (TFT), a voltage is applied to thesource electrode 107 to induce electric field between the pixelelectrode 114 and the common electrode 103 disposed so as to confrontthe pixel electrode 114. The electric field keeps the liquid crystalmolecules 141 substantially in parallel to the direction of the electricfield formed between the pixel electrode 114 and the common electrode103. By setting the polarization transmission axis of the polarizingplate 151 at a predetermined angle, the light transmittance can bevaried due to the motion of the liquid crystal molecules as describedabove.

[0056] Next, a method of manufacturing the liquid crystal display deviceaccording to the first mode will be briefly described.

[0057] A Cr film is first formed, and subjected to a patterningtreatment by using well-known photolithography technique and etchingtechnique, thereby forming the gate electrode on the glass substrate 101as shown in FIG. 2A.

[0058] Subsequently, as shown in FIG. 2B, the gate insulating film 104of silicon nitride is formed on the glass substrate 101 (and on the gateelectrode 102), and the semiconductor film 105 of amorphous silicon isformed on the gate electrode 102 through the gate insulating film 104.The semiconductor film 105 may be formed by depositing amorphous siliconon the gate insulating film 104 and then patterning the amorphoussilicon film by the well-known photolithography technique and etchingtechnique.

[0059] Subsequently, the drain electrode 106 and the source electrode107 are formed of molybdenum so as to be overlapped with a part of thepattern of the semiconductor film 105 as shown in FIG. 2C. Thereafter,the protection film 108 is formed on the gate insulating film 104 so asto cover the drain electrode 106, the source electrode 107 and thesemiconductor film 105 as shown in FIG. 2D.

[0060] Subsequently, as shown in FIG. 2E, the color filter layer 110 andthe light shielding portion 111 are formed on the protection film 108,and then the common electrode 103 of aluminum is formed on the lightshielding portion 111 by the photolithography technique and the etchingtechnique. The color filter layer 110 is formed of a resin filmcontaining red, green or blue dye or pigment. The light shieldingportion 111 may be formed of a resin film containing black dye orpigment. Alternatively, the light shielding portion my be formed ofmetal.

[0061] The color filter layer 110 may be formed by using apigment-dispersed resist in which pigment having a desired opticalcharacteristic such as red or the like is dispersed in negative typephotosensitive resin containing acrylic resin as a base. First, thepigment-dispersed resist is coated on the protection film 108 to form aresist film thereof. Subsequently, the resist film is exposed to lightby using a photomask so that the light is selectively irradiated topredetermined areas, that is, pixel areas arranged in a matrix form.After the exposure step, the result is developed with predetermineddeveloping liquid to form a predetermined pattern. These steps arerepeated three times for three colors of red, green and blue forexample, thereby forming the color filter layer 110.

[0062] Subsequently, an overcoat layer 112 of transparent insulatingmaterial is formed on the color filter layer 110 and the light shieldingportion 111 as well as the common electrode 103 as shown in FIG. 3F. Theovercoat layer 112 may be formed of thermosetting resin such as acrylicresin or the like. Alternatively, photocurable transparent resin may beused for the overcoat layer 112.

[0063] Subsequently, a through hole is formed and then the pixelelectrode 114 to be connected to the source electrode 107 through thethrough hole is formed on the overcoat layer 112 as shown in FIG. 3G.

[0064] Thereafter, the orientation film 115 is formed, and then theliquid crystal composition layer 140 is formed. Besides, the polarizingplate 151 is formed on one surface of the counter substrate 131, and theorientation film 132 is formed on the opposite surface of the countersubstrate 131 to the polarizing-plate formed surface. Thereafter, theliquid crystal composition layer 140 is hermetically filled between theglass substrate 101 and the counter substrate 131 through a sealingmember containing a gap member, thereby completing the liquid crystaldisplay device as shown in FIG. 1.

[0065] As described above, according to the first mode, electric fieldis formed between the pixel electrode 114 disposed on the color filterlayer 110 and the common electrode 103 disposed so as to confront thepixel electrode 114, whereby the liquid crystal molecules 141 disposedon the above electrodes are driven.

[0066] Therefore, according to the first mode, the color filter layer110 and the liquid crystal composition layer 140 are disposed so as tosandwich the pixel electrode 114 and the common electrode 103therebetween. Accordingly, the electric field which is induced by thepixel electrode 114 and the common electrode 103 to move the liquidcrystal molecules 141 has no effect on the color filter layer 110.

[0067] Above the common electrode 103, the liquid crystal compositionlayer 140 is formed on the overcoat layer 112, however, the overcoatlayer 112 is little charged up.

[0068] As described above, according to the first mode, it is preventedfrom applying undesired electric field to the liquid crystal compositionlayer 140 from the upper and lower sides, so that the deterioration ofthe display characteristic can be suppressed unlike the prior art.

[0069] Further, the pixel electrode 114 and the common electrode 103 andthe common electrode wire 103 a are formed through the overcoat layer112, and the pixel electrode 114 and the common electrode wire 103 a areprevented from coming into contact with each other.

[0070] [Second Mode 2]

[0071] First, a liquid crystal display device according to a second modeof the present invention will be described with reference to FIGS. 4Aand 4B. FIG. 4A is a cross-sectional view of BB′ line of FIG. 4B.

[0072] In the liquid crystal display device of the second mode, a gateelectrode 402 of Cr is disposed on a glass substrate 401, and a gateinsulating film 404 of silicon nitride so as to cover the gate electrode402.

[0073] A semiconductor film 405 of amorphous silicon is disposed on thegate electrode 402 through the gate insulating film 404, and itfunctions as an active layer of the thin film transistor.

[0074] A drain electrode 406 and a source electrode 407 are formed ofmolybdenum so as to be overlapped with a part of the pattern of thesemiconductor film 405, and a protection film 408 of silicon nitride isformed so as to cover all the above electrodes. As not shown, each ofthe drain electrode 406 and the source electrode 407 is overlapped witha part of the pattern of the semiconductor film 405 through an amorphoussilicon film doped with n-type impurities. As shown in FIG. 4B, thedrain electrode 406 is connected to a data line 406 a. The abovestructure is the same as the first mode.

[0075] In the second mode, the color filter layer 410 is disposed on theprotection film 408, and the color filter layer 410 is covered by theovercoat layer 412. The overcoat layer 412 is formed of transparentmaterial such as acrylic resin or the like which is hard to charge up.

[0076] A pixel electrode 414 is disposed on the overcoat layer 412 so asto be connected to a draw-out electrode 407 a drawn out from the sourceelectrode 407. The pixel electrode 414 is connected to the draw-outelectrode 407 a through a through hole which penetrates through theprotection film 408, and the overcoat layer 412. The pixel electrode 414is formed of a transparent electrode of ITO (In₂O₃:Sn), and it isdisposed at the center of a one-pixel area so as to divide the one-pixelarea into substantially equal two parts.

[0077] Further, the common electrode wire 403 is formed so as tosurround the one-pixel area. The common electrode wire 403 is disposedon the color filter layer 410 so as to be covered by the overcoat layer412. Viewed from the upper side, the common electrode wire 403 isdisposed so as to hide the drain electrode 406, the data line 406 a, thesource electrode 407 and the gate electrode 402 disposed as the lowerlayers of the common electrode wire 403 and the TFTs constructed by theabove elements, whereby the common electrode wire 403 also serves as alight shielding layer.

[0078] An orientation film 415 is formed on the surface of the activematrix substrate in which the unit pixels thus constructed are arrangedin a matrix form, that is, on the overcoat layer having the pixelelectrode 414 formed thereon. The surface of the orientation film 415 issubjected to the rubbing treatment.

[0079] In addition, an orientation film 432 is formed on a countersubstrate 41 of glass, and the surface of the orientation film 432 issubjected to the rubbing treatment. The glass substrate 401 and thecounter substrate 431 are disposed so that the orientation film 415 andthe orientation film 432 are confronted to each other, and a liquidcrystal composition layer 440 is disposed between the orientation film415 and the orientation film 432. Further, a polarizing plate 451 isformed on the outer surface of each of the glass substrate 401 and thecounter substrate 431.

[0080] As described above, in the second mode, as in the case of thefirst mode, the common electrode wire 403 is disposed on the colorfilter layer 410, and the pixel electrode 414 is disposed on theovercoat layer 412 which is formed so as to cover the common electrodewire 403 and the color filter layer 410. In this case, the commonelectrode wire 403 also serves as a common electrode as in the case ofthe first mode. Further, in the second mode, each pixel is constructedby an area surrounded by the common electrode wire 403 formed in a gridshape, and the pixel electrode 414 is disposed so as to pass through thecenter portion of the area and partition the area into equal two parts.

[0081] In the TFT liquid crystal display device thus constructed, whenno electric field is applied to the liquid crystal composition layer440, the liquid crystal molecules in the liquid crystal compositionlayer 440 are kept substantially in parallel to the extending directionof these electrodes. That is, the liquid crystal molecules are disposedso that the intersecting angle between the direction of the major axis(optical axis) of the liquid crystal molecules and the direction of theelectric field formed between the pixel electrode 414 and the commonelectrode wire 403 is set to be above 45 degrees and less than 90degrees. The orientation direction of the glass substrate 401 and thecounter substrate 431 disposed so as to confront each other is set to beparallel to the orientation direction of the liquid crystal molecules.The permittivity anisotropy of the liquid crystal molecules is set to apositive value.

[0082] Here, when a voltage is applied to the gate electrode 402 toswitch on the thin film transistor (TFT), the voltage is applied to thesource electrode 407 to induce the electric field between the pixelelectrode and the common electrode wire 403 disposed so as to confrontthe pixel electrode 414. The electric field keeps the liquid crystalmolecules 441 substantially in parallel to the direction of the electricfield formed between the pixel electrode 414 and the common electrodewire 403. By disposing the polarization transmission axis of thepolarizing plates 451 at a predetermined angle, the light transmittancecan be varied due to the motion of the liquid crystal molecules asdescribed above.

[0083] As described above, in the second mode, the electric field isformed between the pixel electrode 414 disposed on the color filterlayer 410 and the common electrode wire 403 disposed so as to confrontthe pixel electrode 414, thereby driving the liquid crystal molecules441 disposed on these electrodes.

[0084] That is, in the second mode, the color filter layer 410 and theliquid crystal composition layer 440 are disposed so as to sandwich thepixel electrode 414 and the common electrode wire 403 therebetween.Accordingly, the electric field which is formed by the pixel electrode414 and the common electrode wire 403 to move the liquid crystalmolecules 441 has no effect on the color filter layer 410.

[0085] Above the common electrode wire 403, the liquid crystalcomposition layer 440 is formed on the overcoat layer 412, however, theovercoat layer 412 is little charged up.

[0086] As described above, according to the second mode, it can beprevented that undesired electric field is applied to the liquid crystalcomposition layer 440 from the upper and lower sides at all times.Therefore, unlike the prior art, the deterioration of the displaycharacteristic can be suppressed.

[0087] The pixel electrode 414 and the common electrode wire 403 areformed through the overcoat layer 412, so that the pixel electrode 414and the common electrode wire 403 are prevented from coming into contactwith each other. According to the second mode, the common electrode wire403 serves as a light shielding layer, so that the manufacturing processof the color filter layer can be simplified.

[0088] According to the first and second modes, a pair of commonelectrode and pixel electrode are provided for one pixel, however, thepresent invention is not limited to the above modes. Plural pairs ofcommon electrodes and pixel electrodes may be provided in each pixelarea. For example, the electrodes may be designed in a comb-shape anddisposed so as to confront each other. With this structure, the distancebetween the pixel electrode and the common electrode can be shortenedeven when each pixel is large, and thus the voltage applied to drive theliquid crystal can be reduced.

[0089] [Third Mode]

[0090] Next, a liquid crystal display device according to a third modeof the present invention will be described with reference to FIGS. 5A to5C. FIG. 5A is a plan view showing some pixels of the liquid crystaldisplay device, and FIGS. 5B and 5C are cross-sectional views takenalong A-A′ line and B-B′ line of FIG. 5A.

[0091] The liquid crystal display device of the third mode is the sameas the first mode in that a gate electrode 505 is formed on a glasssubstrate 501, a thin film transistor comprising a drain electrode 506and a source electrode 507 is formed through a gate insulating film 504,and a passivation film 512 is formed on the thin film transistor.Further, a color filter layer 517 is formed on the passivation film 512,and a first overcoat layer 513 is formed so as to cover the color filterlayer 513. The overcoat layer 513 is formed of a transparent insulatingfilm which is hard to be charged up.

[0092] On the first overcoat layer 513 is disposed a pixel electrode 508connected to the source electrode 507 through a through hole which isformed so as to penetrate through the passivation film 512 and the firstovercoat layer 513.

[0093] A second overcoat layer 514 is further formed so as to cover allthe above elements, and a common electrode 509 drawn out through acommon electrode wire is formed on the second overcoat layer 514. Here,in order to enable the electric field between the common electrode 509and the pixel electrode to be applied to the liquid crystal layer 515,the second overcoat layer 513 is preferably made thin so as to have athickness of about 0.1 to 1 μm, and further it may be formed of amaterial having a high permittivity (dielectric constant).

[0094] Accordingly, in the third mode, the pixel electrode 508 isprovided on the first overcoat 513 disposed on the color filter 517, andthe common electrode 509 is disposed on the second overcoat layer whichis formed so as to cover the above elements. The gap between the pixelelectrode 508 and the common electrode 509 forms one pixel. The commonelectrode 509 is disposed on the wire and TFT, and it serves as a lightshielding member as in the case of the second mode.

[0095] The third mode is similar to the first mode in that theorientation films are formed on the surface of the active matrixsubstrate on which the unit pixels designed as described above aredisposed in a matrix arrangement and on the surface of the countersubstrate, both the substrates are subjected to rubbing treatment in apredetermined direction and the liquid crystal is driven by usinglaterally-directing electric field occurring between the pixel electrodeand the common electrode disposed on the active matrix substrate tothereby vary the light transmissivity. The liquid crystal layer 515 issandwiched between the counter substrate 516 and the second overcoatlayer 514.

[0096] Next, a method of manufacturing the liquid crystal display deviceaccording to the third mode described above will be briefly described.

[0097] As in the case of the first mode, as shown in FIG. 6A, a thinfilm transistor is formed on the glass substrate, the passivation film512 for protecting the thin film transistor and the glass substrate isdeposited, and then a color filter is formed by using pigment-dispersedtype photosensitive acrylic resin or the like.

[0098] Subsequently, as shown in FIG. 6B, the first overcoat layer isformed by using transparent photosensitive acrylic resin or the like, athrough hole 518 is formed in the first overcoat layer and at the sametime a through hole is formed on the passivation film 512.

[0099] Subsequently, as shown in FIG. 6C, the pixel electrode 508 to beconnected to the source electrode 508 through the through hole 518 isformed on the first overcoat layer by using ITO or the like.

[0100] Subsequently, as shown in FIG. 6D, the second overcoat layer isformed. When the second overcoat film is formed of a photosensitiveorganic film by using a coating method or the like, the through hole 508is flattened, and both of the pixel electrode and the common electrodecan be prevented from being short-circuited to each other. Therefore,this method is preferable.

[0101] Thereafter, as shown in FIG. 6E, the common electrode 509 isformed of chrome/molybdenum or the like.

[0102] As described above, according to the third mode, undesiredelectric field is prevented from being applied to the liquid crystallayer 515 from the upper and lower sides at all times, and thus thedevice of the third mode has such a structure that the displaydeterioration hardly occurs unlike the prior art. Further, since thethrough hole on the first overcoat layer is flattened by the secondovercoat layer, the short-circuit between the pixel electrode and thecommon electrode can be prevented.

[0103] [Fourth Mode]

[0104] Next, the liquid crystal display device according to the fourthmode of the present invention will be described with reference to FIG.7. FIG. 7A is a plan view showing some pixel of the liquid crystaldisplay device, and FIGS. 7B and 7C are cross-sectional views takenalong A-A′ line and B-B′ line of FIG. 7A, respectively.

[0105] In the liquid crystal display device according to the fourth modeof the present invention, the manufacturing processing thereof is thesame as the first mode in that a gate electrode 705 is formed on a TFTglass substrate, a thin film transistor comprising a drain electrode 706and a source electrode 707 is formed through a gate insulating film 704,and a passivation film 712 is formed on the thin film transistor. Acolor filter layer 717 is formed on the passivation film 712, and afirst overcoat layer 713 is formed so as to cover the color filter layer717. The overcoat layer 713 is formed of a transparent insultingmaterial which is hardly charged up. A common electrode 709 drawn outthrough a common electrode wire is formed on the passivation film 712and the first overcoat layer 713. Further, a second overcoat layer 714is formed so as to cover the above elements, and a pixel electrode to beconnected to the source electrode 707 through a through hole penetratingthrough the second overcoat layer is disposed.

[0106] Here, in order to enable the electric field between the commonelectrode and the pixel electrode from being applied to the liquidcrystal layer 715, it is preferable that the second overcoat layer ismade thin so as to have a thickness of about 0.1 to 1 μm and formed of amaterial having a high permittivity.

[0107] Accordingly, in the fourth mode, the common electrode 709 isdisposed on the first overcoat 713 on the color filter 717, and thepixel electrode 708 is disposed on the second overcoat layer formed soas to cover the first overcoat 713 and the common electrode 709. Thearea sandwiched between the pixel electrode 709 and the common electrode709 forms one pixel. The common electrode 709 is disposed on the wireand TFT, and it serves as a light shielding member as in the case of thesecond mode.

[0108] The fourth mode is similar to the first mode in that theorientation films are formed on the surface of the active matrixsubstrate on which the unit pixels designed as described above aredisposed in a matrix arrangement and on the surface of the countersubstrate, both the substrates are subjected to rubbing treatment in apredetermined direction and the liquid crystal is driven by usinglaterally-directing electric field occurring between the pixel electrodeand the common electrode disposed on the active matrix substrate tothereby vary the light transmissivity. The liquid crystal layer 715 issandwiched between the counter substrate 716 and the second overcoatlayer 714.

[0109] Next, a method of manufacturing the liquid crystal display deviceaccording to the fourth mode described above will be briefly described.

[0110] As in the case of the first mode, as shown in FIG. 8A, a thinfilm transistor is formed on the glass substrate 710, the passivationfilm 712 for protecting the thin film transistor and the glass substrateis deposited, and then a color filter is formed by usingpigment-dispersed type photosensitive acrylic resin or the like.

[0111] Subsequently, as shown in FIG. 8B, after the first overcoat layeris coated, the common electrode 709 is patterned by using metal such aschromium/molybdenum or the like.

[0112] Subsequently, as shown in FIG. 8c, after the second overcoat filmis coated, the through hole penetrating trough the first and secondovercoat films and the passivation films is formed.

[0113] Finally, as shown in FIG. 8D, the pixel electrode 908 to beconnected to the source electrode 707 through the through hole 718 isformed on the second overcoat layer by using ITO or the like.

[0114] As described above, according to the fourth mode of the presentinvention, the liquid crystal layer 715 has such a structure that thedisplay degradation hardly occurs unlike the prior art because undesiredelectric field can be prevented from being applied to the liquid crystallayer 715 from both the upper and lower sides at all times. Further, thethrough hole is formed by collectively performing patterning treatmenton the first and second overcoat layer, so that the number ofmanufacturing steps is smaller than that of the third mode.

[0115] [Fifth Mode]

[0116] Next, a liquid crystal display device according to a fifth modeof the present invention will be described with reference to FIGS. 9Aand 9B. FIG. 9A is a cross-sectional view taken along A-A′ line of aplan view of FIG. 9B.

[0117] A vertical orientation film 915 is formed on the surface of theactive matrix substrate on which the unit pixels designed in the samemanner as the first mode are disposed in a matrix arrangement, that is,on the overcoat layer 912 on which the pixel electrode 914 is formed.The surface of the orientation film 915 may be subjected to the rubbingtreatment or the optical orientation processing, if necessary.

[0118] Further, a vertical orientation film 932 is also formed on acounter substrate 931 formed of a transparent substrate, and the rubbingor optical orientation treatment is conducted on this orientation film932, as occasion demands. In order to prevent degradation of imagequality due to static electricity, a transparent conductive film such asITO or the like may be provided on the opposite surface of the countersubstrate to the orientation-film provided surface.

[0119] The substrate 901 and the counter substrate 931 are disposed sothat the surfaces thereof on which the orientation film 915 and theorientation film 932 are formed respectively are confronted to eachother, and a liquid crystal layer 940 is disposed therebetween. When thedisplay device is used as a transmission type, a polarizing plate 951 isformed on the outer surface of each of the substrate 901 and the countersubstrate 931. The light shielding portion 911 through which the colorfilter 910 is partitioned is formed so that a partial area thereof isdisposed on the thin film transistor formed of the semiconductor film905.

[0120] In the active matrix type liquid crystal display device thusconstructed, when no electric field is applied to the liquid crystallayer 940, the liquid crystal molecules in the liquid crystal layer 940are oriented substantially vertically to the substrates. Thepermittivity anisotropy of the liquid crystal is set to a positivevalue.

[0121] Here, when a voltage is applied to the gate electrode 902 toswitch on the thin film transistor (TFT), a voltage is applied to thesource electrode 907, and electric field is induced between the pixelelectrode 914 and the common electrode 903 disposed so as to confrontthe pixel electrode 914. The electric field fells the liquid crystalmolecules 941 substantially in parallel to the direction of the electricfield formed between the pixel electrode 914 and the common electrode903, that is, the substrate direction.

[0122] At this time, since the direction of the electric field is notperfectly parallel to the substrate, the liquid crystal moleculesbetween the electrodes are separately felled in two directions.

[0123] As described above, according to the manufacturing method of thepresent invention, the direction in which the liquid crystal moleculesare felled can be automatically divided into two directions withoutapplying any special treatment on the orientation film, therebyachieving a wide angle of visibility.

[0124] However, the areas in which the liquid crystal molecules arefelled in different directions (hereinafter referred to as“molecule-felling area”) are controlled by only the direction of theelectric field, and they are not clearly separated from each other.Therefore, when the orientation state of the liquid crystal is bad, theboundary between these areas may be shifted within a pixel in somedisplay frames, resulting in occurrence of display failure.

[0125] Therefore, in order to more perfectly control the boundary atwhich the felling direction of the liquid crystal molecules is varied,the boundary may be fixed in the following manner.

[0126] As a method of fixing the boundary, rubbing treatment which isvaried every area may be performed as shown in FIG. 10.

[0127] First, as shown in FIG. 10A, a resist pattern 1001 is formed onthe vertical orientation film 915 on one of different molecule-fellingareas within the pixel, and a rubbing roll 1010 is shifted in apredetermined direction under the above state. Accordingly, an area ofthe vertical orientation film 915 which is not covered by the resistpattern 1001 is subjected to the rubbing treatment in the predetermineddirection. However, in this step, the area covered by the resist pattern1001 is not subjected to the rubbing treatment.

[0128] Subsequently, after the resist pattern 1001 is removed, as shownin FIG. 10B, a resist pattern 1002 is formed on the vertical orientationfilm 915 on the other molecule-felling area within the pixel. That is,the resist pattern 1002 is formed so as to cover the area which has beensubjected to the rubbing treatment. Under this state, the rubbing roll1010 is shifted in the opposite direction to the above direction.

[0129] Through the above operation, the area which is not covered by theresist pattern 1002 of the vertical orientation film 915 is subjected tothe rubbing treatment in a direction different from that of the areawhich has been subjected to the rubbing treatment. In this rubbingtreatment, the area which has been already subjected to the rubbingtreatment is covered by the resist pattern 1002, and thus this area isprevented from being subjected to the rubbing treatment again.

[0130] After the resist pattern 1002 is removed, the verticalorientation film 932 of the counter substrate 931 is subjected to thesame treatment, and the liquid crystal layer 940 is disposed betweenthese substrates as shown in FIG. 10C. As a result, the liquid crystalmolecules 941 are felled in the different directions with respect to theboundary. That is, the divisional areas can be fixed as described above.

[0131] In order to more perfectly control the boundary at which thefelling direction of the liquid crystal molecules is varied, theboundary may be fixed by the following methods. These two methods arebased on use of an optical orientation film whose orientation directionis settled by irradiating polarized light.

[0132] More specifically, as shown in FIG. 11, when a verticalorientation film 915 formed of an optical orientation film is formed, amask 1101 is disposed to light-shield one molecule-felling area withrespect to a specific boundary, and under this state polarized light1110 is irradiated from the upper slant direction, thereby setting theorientation state of an area which is not covered by the mask 1101 ofthe vertical orientation film 915. However, in this step, theorientation state is not set to the area covered by the mask 1101.

[0133] Subsequently, as shown in FIG. 11B, a mask 1102 is disposed onthe vertical orientation film 915 on the other area with respect to theboundary within the pixel. That is, the mask 1102 is disposed so as tocover the area whose orientation state has been already set. Under thisstate, polarized light is irradiated from the slant upper directionopposite to the above slant upper direction, whereby the orientationstate of the area which is not covered by the mask 1102 of the verticalorientation film 915 is set to a specific orientation state.Accordingly, the orientation state of the area which is not covered bythe mask 1102 of the vertical orientation film 915 is set in a directiondifferent from that of the area whose orientation state has been alreadyset. In this treatment, the area whose orientation state has been set iscoated by the mask 1102 and thus it is exposed to light, so that theorientation state of the area is not set again.

[0134] As shown in FIG. 11C, the same treatment is conducted on thevertical orientation film 932 of the counter substrate 931, and theliquid crystal layer 940 is disposed between both the substrates. As aresult, in the liquid crystal layer 940, the liquid crystal molecules941 are felled in different directions with respect to the boundary.That is, the divisional areas can be fixed as described above.

[0135] As the light orientation film may be used material having afunctional group such as a cinnamic acid group which can control theorientation of the liquid crystal by polarized light, or polymer whosephotosensitive groups are polymerized by irradiation of polarized lightas described in “AM-LCD'96/IDW'96 Digest of Technical Papers), p 337.

[0136] Further, when the disturbance of the orientation of the liquidcrystal cannot be controlled by using any one of the above two methods,the orientation state of the liquid crystal may be stored by usingorganic polymer material. This is performed as follows. That is,monomers or olygomers of the material are first introduced in the liquidcrystal, and then the liquid crystal is set to a specific orientationdirection state. Under this state, ultraviolet ray is irradiated topolymerize the monomers into polymer. As a result, the orientation stateof the liquid crystal is stored.

[0137] Photocurable monomers or thermosetting monomers or olygomers ofthese monomers may be sued as the monomers, olygomers of the organicpolymer material as described above. Further, the material may containother components insofar it contains the above components. “Photocurablemonomers or olygomers” used in the present invention are not limited tomaterials which react with visible light, and may containtultraviolet-ray curable monomers or the like which react withultraviolet ray. From the viewpoint of operability, the latter materialsare preferable.

[0138] Each of the above polymer compounds may has a similar structureto that of the liquid crystal molecules containing monomers, olygomersexhibiting liquid crystallinity, however, it may be such flexiblematerial having alkylene chains because it does not necessarily aim toorient the liquid crystal. Further, it may be monomer havingmonofunctionality, bifunctionality or multifunctionality oftrifunctionality or more. The following materials may be as theultraviolet-ray curable monomers used in the present invention.

[0139] First, the following monofunctional acrylate compounds may beused 2-ethylhexyl acrylate, butyletyl acrylate, butoxyethyl acrylate,2-cyanoethyl acryvlate, benzyl acrylate, cyclohexyl acrylate,2-hydroxypropyl acrylate, 2-etoxyethyl acrylate, N,N-ethylaminoethylacrylate, N,N-dimethylaminoethyl acrylate, dicyclopentanyl acrylate,dicyclopentenyl acrylate, glycizyl acrylate, tetrahydrofurfurylacrylate, isobonyl acrylate, isodecyl acrylate, lauryl acrylate,morpholine acrylate, phenoxyethyl acrylate, phenoxydiethyleneglycolacrylate, 2,2,2-trifluoroethyl acrylate, 2,2,3,3,3-pentafluoropropylacrylate, 2,2,3,3-tetrafluoropropyl acrylate,2,2,3,4,4,4-hexafluorobutyl acrylate or the like, etc.

[0140] Further, the following monofunctional methacrylate compounds maybe used: 2-ethylhexyl methacrylate, butyletyl methacrylate, butoxyethylmethacrylate, 2-cyanoethyl methacrylate, benzyl methacrylate, cyclohexylmemtacrylate, 2-hydroxypropyl methacrylate, 2-etoxyethyl methacrylate,N,N-diethylaminoethyl methacrylate, N,N-dimethylaminoethyl methacrylate,dicyclopentanyl methacrylate, dicyclopentenyl methacrylate, glycizylmethacrylate, tetrahydrofurfuryl methacrylate, isobonyl methacrylate,isodecyl methacrylate, lauryl methacrylate, morpholine methacrylate,phenoxyethyl methacrylate, phenoxydiethyleneglycol memthacrylate,2,2,2-trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropylmethacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate or the like, etc.

[0141] Further, the following multifunctional acrylate compounds may beused: 4,4′-biphenyl diacrylate, diethylstilbestrol diacrylate,1,4-bisacryloyloxybenzene, 4,4′-bisacryloyloxydiphenylether,4,4′-bisacryloyl oxydiphenylmetane,3,9-bis[1,1-dimethyl-2-acryloyloxyethyl]-2,4,8,10-tetraspiro[5,5]undecane,α, α ′-bis[4-acryloyloxylphenyl]-1,4-diisopropyl benzen,1,4-bisacryloyloxytetrafluorobenzene,4,4′-bisacryloyloxyoctafluorobiphenyl, diethyleneglycol diacrylate,1,4-butanediol diacrylate, 1,3-butyleneglocol diacrylate,dicyclopentanyl diacrylate, glycerol diacrylate, 1,6-hexanedioldiacrylate, neopentylglycol diacrylate, tetraethyleneglycol diacrylate,trimethylolpropane triacrylate, pentaerythritol tetraacrylate,pentaerythritol triacrylate, ditrimethylolpropane tetraacylate,dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, 4,4′-diacryloyloxystilbene,4,4′-diacryloyloxydimethylstilbene, 4,4′-diacryloyloxydiethylstilbene,4,4′=diacryloyloxydipropylstilbene, 4,4′-diacryloyloxydibutylstilbene,4,4′-diacryloyloxydipentylstilbene, 4,4′-diacryloyloxydihexylstilbene,4,4′-diacryloyloxydifluorostilbene,2,2,3,3,4,4-hexafluoropentanediol-1,5-diacrylate,1,1,2,2,3,3-hexafluoroproyl-1,3-diacrylate, urethane acrylate olygomer,etc.

[0142] Still further, the following multifunctional methacrylatecompounds may be used: diethyleneglycol dimethacrylate, 1,4-butanedioldimethacrylate, 1,3-butyleneglocol dimethacrylate, dicyclopentanyldimethacrylate, glycerol dimethacrylate, 1,6-hexanediol dimethacrylate,neopentylglycol dimethacrylate, tetraethyleneglycol dimethacrylate,trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate,pentaerythritol trimethacrylate, ditrimethylolpropane tetramethacylate,dipentaerythritol hexamethacrylate, dipentaerythritol monohydroxypentamethacrylate, 2,2,3,3,4,4-hexafluoropentanediol-1,5-dimethacrylate,urethane methacrylate olygomer, etc. In addition, other styrene,aminostyrene, vinyl acetate, etc. may be used. However, the materialusable in the present invention is not limited to the above materials.

[0143] In the present invention, the driving voltage of each element ofthe liquid crystal display device is also effected by the interfacemutual interaction between the polymer material and the liquid crystalmaterial, and thus the material may be polymer compound having fluorineelement. Such a polymer compound may be synthesized from compoundscontaining 2,2,3,3,4,4-hexafluoropentanediol-1,5-diacrylate,1,1,2,2,3,3-hexafluoropropyl-1,3-diacrylate, 2,2,2-trifluoroethylacrylate, 2,2,3,3,3-pentafluoropropyl acrylate,2,2,3,3-tetrafluoropropyl acrylate, 2,2,3,4,4,4-hexafluorobutylacrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropylmethacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, urethaneacrylate olygomer or the like. However, the present invention is notlimited to the above materials. When light or ultraviolet-ray curablemonomer is used as a polymer compound used in the present invention, aninitiator for light or ultraviolet ray may be used.

[0144] As the initiator may be used various kinds of materials such asacetophenone group such as 2,2-diethoxyacetophenone,2-hydroxy-2-methyl-1-phenyl-1-one,1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, or1-(4-dodecylphenyl)-2-hydroxy-2-methylpropane-1-one, benzoyl group suchas benzoinmethylether, benzoinethylether, benzildimethylketal or thelike, benzophenone group such as benzophenone, benzoil benzoic acid,4-phenylbenzophenone, 3,3-dimethyl-4-methoxybenzophenone or the like,thioxanthon, 2-chlorthioxanthon, 2-methylthioxanthon, or the like,diazonium salt grout, sulfonium salt group, iodonium salt group,selenium salt group or the like.

[0145] If the polarized light transmission axes of the polarizing plate951 are disposed to be at a predetermined angle, the lighttransmissivity can be varied by the motion of the liquid crystalmolecules.

[0146] Further, when the polarized light transmission axes are set to beperpendicular to each other, the display mode of the display device isset to a normally black mode, however, in order to avoid theviewing-angle-dependence of the retardation of the initial liquidcrystal orientation, a negative uniaxial compensation film and apositive uniaxial compensation film may be used in combination, wherebythe viewing-angle-dependence of the black state is avoided, therebyenhancing the image quality and increasing the angle of visibility.

[0147] As described above, according to the fifth mode, the liquidcrystal layer 940 can be preventing from falling into such a state thatundesired electric field is applied to the liquid crystal layer in theup-and-down direction at all times, so that the degradation of thedisplay characteristic hardly occurs unlike the conventional displaydevice. Further, by applying the voltage to the liquid crystalmolecules, the molecules are felled from the orientation state in whichthe molecules are oriented substantially perpendicular to the substrate,and thus there does not occur any staining when the device is viewedfrom a slant direction, and a wide angle-of-visibility characteristic isgiven.

EMBODIMENTS

[0148] Embodiments according to the present invention will be describedhereunder in more detail.

[0149] [First Embodiment]

[0150] A substrate having an array of amorphous silicon thin filmtransistors (TFT) was formed on a glass substrate by repeating both of afilm forming process and a lithography process. The TFT array comprisesa gate-chrome layer, a silicon nitride-gate insulating layer, anamorphous silicon-semiconductor layer, a drain/source-molybdenum layerwhich were arranged from the substrate side in this order (see FIG. 2C).Thereafter, a protection film was formed of silicon nitride so as tocover the above layers.

[0151] Subsequently, for example a color filter layer of green wascoated on the protection layer, heated and dried and formed byphotolithography. The same process was repeated to form red, blue colorfilter layers, thereby forming a color filter layer. A light shieldingportion was formed by using resin containing black pigment in the samemanner. Thereafter, a common electrode was formed of chrome, and then anovercoat layer of acrylic resin was coated and then heated for one hourat 200° C.

[0152] Subsequently, a through hole was formed so as to extend to thesource electrode by using photolithography, etching. A pixel electrodewas formed of chrome, and SE1211 produced by Nissan Chemical Company wascoated as a vertical orientation film and then heated for one hour at200° C.

[0153] Thereafter, SE1211 produced by Nissan Chemical Company was coatedas a vertical orientation film on a glass substrate having ITO formed onthe back surface thereof, and then heated for one hour at 200° C.,thereby forming a counter substrate.

[0154] A seal member was coated on the peripheral portions of thesubstrates. These substrates were attached to each other through aspacer member so that the orientation-film formed surfaces thereof faceeach other, and then heated for three hour at 160° C. to cure the sealmember. At this time, the counter substrate was a mere substrate, andthus it is unnecessary to positionally match the substrates with highprecision.

[0155] Thereafter, nematic liquid crystal having positive permittivityanisotropy was injected into the gap between the substrates, and theinjection hole was sealed by photocurable resin. An optically negativecompensation film whose Δnd is equal in absolute value, however,opposite in sign to Δnd of the liquid crystal layer was attached, andthen polarizing plates were attached to the upper and lower substratesso that the transmission axes thereof were perpendicular to each other.

[0156] Upon measuring the angle-of-visibility characteristic of a panelthus fabricated, no gradation inversion was observed, and such anexcellent angle-of-visibility characteristic that an extremely wide areahaving high contrast is provided can be obtained. Particularly, in thisembodiment, there is not observed any staining which has been hithertoobserved on a usual panel driven by lateral electric field when thepanel is viewed from the slant direction. Further, no color shade isobserved, and an excellent angle-of-visibility characteristic isobtained.

[0157] [Second Embodiment]

[0158] As in the case of the first embodiment, an array of amorphoussilicon thin film transistors (TFT) was formed by repeating both thefilm forming process and the lithography process. TFT comprised agate-chrome layer, a silicon nitride-gate insulating layer, a amorphoussilicon-semiconductor layer and a drain/source-molybdenum layer whichwere arranged from the substrate side in this order as in the case ofthe first embodiment.

[0159] A protection film of silicon nitride was formed so as to coverthe above layers, and red, blue and green color filter layers wereformed in the same manner as the first embodiment. After a commonelectrode was formed of chrome, an overcoat layer of acrylic resin wascoated and heated for one hour at 200° C.

[0160] Subsequently, a through hole was formed so as to extend to thesource electrode, and a pixel electrode is formed by using ITO. SE1211produced by Nissan Chemical Company was coated as a vertical orientationfilm and then heated for one hour at 200° C. in the same manner.

[0161] A seal member was coated on the peripheral portions of thesubstrates, and both the substrates were attached to each other througha spacer member so that the orientation-film coated surfaces thereof areconfronted to each other, and heated for three hours at 160° C., therebycuring the seal member. At this time, the counter substrate was a meresubstrate, and thus it is unnecessary to positionally match thesubstrates with high precision.

[0162] Thereafter, nematic liquid crystal having positive permittivityanisotropy was injected into the gap between the substrates, and theinjection hole was sealed by photocurable resin. An optically negativecompensation film whose Δnd is equal in absolute value, however,opposite in sign to Δnd of the liquid crystal layer was attached, andthen polarizing plates were attached to the upper and lower substratesso that the transmission axes thereof were perpendicular to each other.

[0163] Upon measuring the angle-of-visibility characteristic of a panelthus fabricated, no gradation inversion was observed, and such anexcellent angle-of-visibility characteristic that an extremely wide areahaving high contrast is provided can be obtained. Particularly, in thisembodiment, there is not observed any staining which has been hithertoobserved on a usual panel driven by lateral electric field when thepanel is viewed from the slant direction. Further, no color shade isobserved, and an excellent angle-of-visibility characteristic isobtained. Since the pixel electrode was formed of ITO, the openingdegree was high and thus light display could be obtained.

[0164] As described above, according to the present invention, in theliquid crystal device having the transparent first and secondsubstrates, the liquid crystal layer sandwiched between the first andsecond substrates and the color filter layer, the color filter layer isdisposed on the first substrate, and the liquid crystal layer isdisposed between the color filter layer and the second substrate.Further, on the first substrate below the color filter layer areprovided plural scan signal electrodes, plural video signal electrodesarranged so as to cross the scan signal electrodes in a matrix form, andplural thin film transistors formed in association with the crossingpoints between the scan signal electrodes and the video signalelectrodes. At least one pixel electrode is formed in each of areassurrounded by the plural scan signal electrodes and the plural videosignal electrodes, and each pixel has a common electrode which isconnected over plural pixels through a common electrode wire andsupplies reference potential, and a pixel electrode which is connectedto the corresponding thin film transistor and disposed so as to confrontthe common electrode in the pixel area. The common electrode and thepixel electrode are disposed between the color filter layer and theliquid crystal layer, and the common electrode and the pixel electrodeare disposed in different layers through a layer-insulating film formedof transparent insulating material, and electric field having acomponent which is dominantly parallel to the first substrate occurs inthe liquid crystal layer by applying a voltage across the commonelectrode and the pixel electrode.

[0165] Accordingly, by the electric field generated with the voltageapplied across the common electrode and the pixel electrode, the liquidcrystal of the liquid crystal layer is rotated on a plane which issubstantially parallel to the substrate, and the electric fieldoccurring in the liquid crystal layer has no effect on the color filterlayer. As a result, according to the present invention, charge-up whichpartially occurs in the color filter layer can be suppressed, therebysuppressing occurrence of color shade of the multicolor display typeliquid crystal display device.

What is claimed is:
 1. A liquid crystal display device having atransparent first substrate, a transparent second substrate, and aliquid crystal layer and a color filter layer sandwiched between thefirst and second substrates, comprising: said color filter layerdisposed on said first substrate; said liquid crystal layer disposedbetween said color filter layer and said second substrate; plural scansignal electrodes, video signal electrodes for crossing said scan signalelectrodes in a matrix form and plural thin film transistors formed inassociation with the crossing points between said scan signal electrodesand said video signal electrodes provided on said first substrate belowsaid color filter layer; at least one pixel formed in each of areassurrounded by said plural scan signal electrodes and said video signalelectrodes: each pixel provided with a common electrode which isconnected over plural pixels through a common electrode wire to supplyreference potential, and a pixel electrode which is connected to thecorresponding thin film transistor and disposed so as to confront saidcommon electrode in said pixel area; and said common electrode and saidpixel electrode disposed between said color filter layer and said liquidcrystal layer; wherein said common electrode and said pixel electrodeare disposed in different layers through an interlayer separation filmformed of a transparent insulating material, and wherein electric fieldhaving a component which is dominantly parallel to said first substrateis produced in said liquid crystal layer by applying a voltage acrosssaid common electrode and said pixel electrode, and liquid crystalbefore the voltage is applied thereto is orientated substantially inparallel to said first substrate.
 2. The liquid crystal display deviceas claimed in claim 1 , wherein at least one of said common electrodeand said pixel electrode is formed of a transparent conductive film. 3.The liquid crystal display device as claimed in claim 1 , wherein saidcommon electrode is formed on said color filter layer, said interlayerseparation film is formed on said common electrode, and said pixelelectrode is formed on said interlayer separation film.
 4. The liquidcrystal display device as claimed in claim 1 , wherein an overcoat layerfor protecting said color filter layer is formed on said color filterlayer, said common electrode is formed on said overcoat layer, saidinterlayer separation film is formed on said common electrode, and saidpixel electrode is formed on said interlayer separation film.
 5. Theliquid crystal display device as claimed in claim 1 , wherein anovercoat layer for protecting said color filter layer is formed on saidcolor filter layer, said pixel electrode is formed on said overcoatlayer, said interlayer separation film is formed on said pixelelectrode, and said common electrode is formed on said interlayerseparation film.
 6. The liquid crystal display device as claimed inclaim 1 , wherein said common electrode is formed in a grid shape so asto surround a pixel; said pixel electrode is disposed so as to traversethe pixel; and said common electrode commonly uses a part of said commonelectrode wire.
 7. The liquid crystal display device as claimed in claim1 , wherein a plurality of said common electrodes and said pixelelectrodes are arranged in the pixel.
 8. The liquid crystal displaydevice as claimed in claim 6 , wherein said common electrode is formedso that the thin film transistor is hidden when viewed from the side ofsaid second substrate.
 9. The liquid crystal display device as claimedin claim 6 , wherein said common electrode is formed so that said scansignal electrodes and said video signal electrodes are hidden whenviewed from the side of said second substrate.
 10. A liquid crystaldisplay device having a first substrate, a second substrate, and aliquid crystal layer and a color filter layer sandwiched between thefirst and second substrates, comprising: said color filter layerdisposed on said first substrate; said liquid crystal layer disposedbetween said color filter layer and said second substrate; plural scansignal electrodes, video signal electrodes for crossing said scan signalelectrodes in a matrix form and plural thin film transistors formed inassociation with the crossing points between said scan signal electrodesand said video signal electrodes provided on said first substrate belowsaid color filter layer; at least one pixel formed in each of areassurrounded by said plural scan signal electrodes and said video signalelectrodes; each pixel provided with a common electrode which isconnected over plural pixels through a common electrode wire to supplyreference potential; a pixel electrode which is connected to thecorresponding thin film transistor disposed so as to confront saidcommon electrode in said pixel area; said common electrode and saidpixel electrode disposed between said color filter layer and said liquidcrystal layer; said common electrode and said pixel electrode disposedin different layers through an interlayer separation film formed of atransparent insulating material; wherein electric field having acomponent which is dominantly parallel to said first substrate isproduced in said liquid crystal layer by applying a voltage across saidcommon electrode and said pixel electrode, and wherein liquid crystalbefore the voltage is applied thereto is orientated substantiallyvertically to said first substrate.
 11. The liquid crystal displaydevice as claimed in claim 10 , wherein at least one of said commonelectrode and said pixel electrode is formed of a transparent conductivefilm.
 12. The liquid crystal display device as claimed in claim 10 ,wherein said common electrode is formed on said color filter layer, saidinterlayer separation film is formed on said common electrode, and saidpixel electrode is formed on said interlayer separation film.
 13. Theliquid crystal display device as claimed in claim 10 , wherein anovercoat layer for protecting said color filter layer is formed on saidcolor filter layer, said common electrode is formed on said overcoatlayer, said interlayer separation film is formed on said commonelectrode, and said pixel electrode is formed on said interlayerseparation film.
 14. The liquid crystal display device as claimed inclaim 10 , wherein an overcoat layer for protecting said color filterlayer is formed on said color filter layer, said pixel electrode isformed on said overcoat layer, said interlayer separation film is formedon said pixel electrode, and said common electrode is formed on saidinterlayer separation film.
 15. The liquid crystal display device asclaimed in claim 10 , wherein said common electrode is formed in a gridshape so as to surround a pixel; said pixel electrode is disposed so asto traverse the pixel; and said common electrode commonly uses a part ofsaid common electrode wire.
 16. The liquid crystal display device asclaimed in claim 10 , wherein a plurality of said common electrodes andsaid pixel electrodes are arranged in the pixel.
 17. The liquid crystaldisplay device as claimed in claim 15 , wherein said common electrode isformed so that the thin film transistor is hidden when viewed from theside of said second substrate.
 18. The liquid crystal display device asclaimed in claim 15 , wherein said common electrode is formed so thatsaid scan signal electrodes and said video signal electrodes are hiddenwhen viewed from the side of said second substrate.
 19. The liquidcrystal display device as claimed in claim 10 , wherein an opticallynegative compensation film and an optically positive compensation filmare disposed between said first or second substrate and a polarizingplate to make anisotropy of refractive index of said liquid crystallayer and said compensation film isotropic.
 20. The liquid crystaldisplay device as claimed in claim 19 , wherein a pre-tilt angles arebeforehand formed along two directions in which liquid crystal moleculesare felled when a voltage is applied.
 21. The liquid crystal displaydevice as claimed in claim 19 , wherein a pre-tilt angle is beforehandformed in any one of directions in which liquid crystal molecules arefelled when a voltage is applied.
 22. The liquid crystal display deviceas claimed in claim 10 , wherein liquid crystal contains an organicpolymer compound.
 23. A method of manufacturing a liquid crystal displaydevice comprising a first substrate, a second transparent secondsubstrate, and a liquid crystal layer and a color filter layersandwiched between said first and second substrates, comprising thesteps of: forming said color filter layer on said first substrate;forming said liquid crystal layer between said color filter and saidsecond substrate; forming, on said first substrate below said colorfilter layer, plural scan signal electrodes, plural video signalelectrodes crossing said scan signal electrodes in a matrix form, andplural thin film transistors in association with the crossing pointsbetween said scan signal electrodes and said video signal electrodes;forming at least one pixel in each of areas surrounded by said pluralscan signal electrodes and said plural video signal electrodes; forming,in each pixel, a common electrode which is connected over plural pixelsthrough a common electrode wire to supply reference potential, and apixel electrode which is connected to the corresponding thin filmtransistor and disposed so as to confront said common electrode in saidpixel area; disposing said common electrode and said pixel electrodebetween said color filter layer and said liquid crystal layer, anddisposing said common electrode and said pixel electrode in differentlayers through an interlayer separation film formed of transparentinsulating material; forming liquid crystal so as to be orientedsubstantially vertically to said first substrate when no voltage isapplied across said common electrode and said pixel electrode; andadding an organic material comprising monomers or olygomers into saidliquid crystal, injecting said liquid crystal into the gap between saidfirst substrate and said second substrate, and then polymerizing saidorganic material in said liquid crystal.
 24. A method of manufacturing aliquid crystal display device comprising a first substrate, a secondtransparent second substrate, and a liquid crystal layer and a colorfilter layer sandwiched between said first and second substrates,comprising the steps of: forming said color filter layer on said firstsubstrate; forming said liquid crystal layer between said color filterand said second substrate; forming, on said first substrate below saidcolor filter layer, plural scan signal electrodes, plural video signalelectrodes crossing said scan signal electrodes in a matrix form, andplural thin film transistors in association with the crossing pointsbetween said scan signal electrodes and said video signal electrodes;forming at least one pixel in each of areas surrounded by said pluralscan signal electrodes and said plural video signal electrodes; forming,in each pixel, a common electrode which is connected over plural pixelsthrough a common electrode wire to supply reference potential, and apixel electrode which is connected to the corresponding thin filmtransistor and disposed so as to confront said common electrode in saidpixel area; disposing said common electrode and said pixel electrodebetween said color filter layer and said liquid crystal layer, anddisposing said common electrode and said pixel electrode in differentlayers through an interlayer separation film formed of transparentinsulating material; and forming an optically negative compensation filmand an optically positive compensation film between said first or secondsubstrate and a polarizing plate, and forming, by a rubbing method,pretilt angles along two directions in which liquid crystal moleculesare felled when a voltage is applied to said compensation films.
 25. Amethod of manufacturing a liquid crystal display device comprising afirst substrate, a second transparent second substrate, and a liquidcrystal layer and a color filter layer sandwiched between said first andsecond substrates, comprising the steps of: forming said color filterlayer on said first substrate; forming said liquid crystal layer betweensaid color filter and said second substrate; forming, on said firstsubstrate below said color filter layer, plural scan signal electrodes,plural video signal electrodes crossing said scan signal electrodes in amatrix form, and plural thin film transistors in association with thecrossing points between said scan signal electrodes and said videosignal electrodes; forming at least one pixel in each of areassurrounded by said plural scan signal electrodes and said plural videosignal electrodes; forming, in each pixel, a common electrode which isconnected over plural pixels through a common electrode wire to supplyreference potential, and a pixel electrode which is connected to thecorresponding thin film transistor and disposed so as to confront saidcommon electrode in said pixel area; disposing said common electrode andsaid pixel electrode between said color filter layer and said liquidcrystal layer, and disposing said common electrode and said pixelelectrode in different layers through an interlayer separation filmformed of transparent insulating material; forming liquid crystal so asto be oriented substantially vertically to said first substrate when novoltage is applied across said common electrode and said pixelelectrode; and forming an optically negative compensation film and anoptically positive compensation film between said first or secondsubstrate and a polarizing plate, and forming, by a rubbing method, apretilt angle in any one of directions in which liquid crystal moleculesare felled when a voltage is applied to said compensation films.
 26. Amethod of manufacturing a liquid crystal display device comprising afirst substrate, a second transparent second substrate, and a liquidcrystal layer and a color filter layer sandwiched between said first andsecond substrates, comprising the steps of: forming said color filterlayer on said first substrate; forming said liquid crystal layer betweensaid color filter and said second substrate; forming, on said firstsubstrate below said color filter layer, plural scan signal electrodes,plural video signal electrodes crossing said scan signal electrodes in amatrix form, and plural thin film transistors in association with thecrossing points between said scan signal electrodes and said videosignal electrodes; forming at least one pixel in each of areassurrounded by said plural scan signal electrodes and said plural videosignal electrodes; forming, in each pixel, a common electrode which isconnected over plural pixels through a common electrode wire to supplyreference potential, and a pixel electrode which is connected to thecorresponding thin film transistor and disposed so as to confront saidcommon electrode in said pixel area; disposing said common electrode andsaid pixel electrode between said color filter layer and said liquidcrystal layer, and disposing said common electrode and said pixelelectrode in different layers through an interlayer separation filmformed of transparent insulating material; forming liquid crystal so asto be oriented substantially vertically to said first substrate when novoltage is applied across said common electrode and said pixelelectrode; and forming an optically negative compensation film and anoptically positive compensation film between said first or secondsubstrate and a polarizing plate, and forming, by light irradiation,pretilt angles in two directions in which liquid crystal molecules arefelled when a voltage is applied to said compensation films.
 27. Amethod of manufacturing a liquid crystal display device comprising afirst substrate, a second transparent second substrate, and a liquidcrystal layer and a color filter layer sandwiched between said first andsecond substrates, comprising the steps of: forming said color filterlayer on said first substrate; forming said liquid crystal layer betweensaid color filter and said second substrate; forming, on said firstsubstrate below said color filter layer, plural scan signal electrodes,plural video signal electrodes crossing said scan signal electrodes in amatrix form, and plural thin film transistors in association with thecrossing points between said scan signal electrodes and said videosignal electrodes; forming at least one pixel in each of areassurrounded by said plural scan signal electrodes and said plural videosignal electrodes; forming, in each pixel, a common electrode which isconnected over plural pixels through a common electrode wire to supplyreference potential, and a pixel electrode which is connected to thecorresponding thin film transistor and disposed so as to confront saidcommon electrode in said pixel area; disposing said common electrode andsaid pixel electrode between said color filter layer and said liquidcrystal layer, and disposing said common electrode and said pixelelectrode in different layers through an interlayer separation filmformed of transparent insulating material; forming liquid crystal so asto be oriented substantially vertically to said first substrate when novoltage is applied across said common electrode and said pixelelectrode; and forming an optically negative compensation film and anoptically positive compensation film between said first or secondsubstrate and a polarizing plate, and forming, by light irradiation, apretilt angle in any one of directions in which liquid crystal moleculesare felled when a voltage is applied to said compensation films.
 28. Themethod as claimed in claim 26 , wherein the light irradiation to formingthe pretilt angles is conducted on the surfaces of said compensationfilms from a slant direction.
 29. The method as claimed in claim 28 ,wherein the light irradiation for forming the pretilt angles isconducted by irradiating polarized light the surfaces of saidcompensation films from a slant direction.
 30. The method as claimed inclaim 27 , wherein the light irradiation for forming the pretilt angleis conducted on the surfaces of said compensation films from a slantdirection.
 31. The method as claimed in claim 28 , wherein the lightirradiation for forming the pretilt angles is conducted by irradiatingpolarized light on the surfaces of said compensation films from a slantdirection.
 32. A method of manufacturing a liquid crystal display devicecomprising the steps of: forming a thin film on a transparent substrate;forming a passivation film for protecting said thin film transistor;successively coating, light-exposing, developing and baking pluralphotosensitive color resists to form a color filter; forming a commonelectrode; and forming an interlayer separation film of a transparentinsulating film.
 33. A method of manufacturing a liquid crystal displaydevice comprising the steps of: forming a thin film on a transparentsubstrate; forming a passivation film for protecting said thin filmtransistor; successively coating, light-exposing, developing and bakingplural photosensitive color resists to form a color filter; forming anovercoat film for protecting said color filter; forming a commonelectrode; and forming an interlayer separation film of a transparentinsulating film.
 34. The liquid crystal display device as claimed inclaim 33 , wherein said common electrode is formed in a grid shape so asto surround a pixel; said pixel electrode is disposed so as to traversethe pixel; and said common electrode commonly uses a part of said commonelectrode wire.
 35. The liquid crystal display device as claimed inclaim 33 , wherein a plurality of said common electrodes and said pixelelectrodes are arranged in the pixel.
 36. The liquid crystal displaydevice as claimed in claim 34 , wherein said common electrode is formedin a grid shape so as to surround a pixel; said pixel electrode isdisposed so as to traverse the pixel; and said common electrode commonlyuses a part of said common electrode wire.
 37. The liquid crystaldisplay device as claimed in claim 34 , wherein a plurality of saidcommon electrodes and said pixel electrodes are arranged in the pixel.38. The liquid crystal display device as claimed in claim 35 , whereinsaid common electrode is formed in a grid shape so as to surround apixel; said pixel electrode is disposed so as to traverse the pixel; andsaid common electrode commonly uses a part of said common electrodewire.
 39. The liquid crystal display device as claimed in claim 35 ,wherein a plurality of said common electrodes and said pixel electrodesare arranged in the pixel.